About $1.5 billion per year are estimated to be spent in over-the-counter cold medications in the United States. Inhalation therapy employed for the relief of bronchial spasms, bronchial asthma, bronchitis, the relief of cough, colds and nasal congestion as carried out at the present time requires a pressurized can for expelling a given quantity of an aerosol containing a therapeutic agent such as epinephrine. These containers are expensive, require the patient to follow instructions carefully, and must be administered according to a set schedule. Other vaporizers that are sometimes used are even more complex. Electric nebulizers and hot water vaporizers are examples. In addition to the expense, these products cannot be used out of doors or away from home. Consequently, they are unsuitable for use at the work place or while riding in a car. Because of these problems, decongestants such as camphor which are intended to be applied to the throat and chest are sometimes used to help relieve cough or cold symptoms. A decongestant of this type typically has a petrolatum base, giving it the consistency of petroleum jelly. One such product is sold under the trademark VICK'S VapoRub.RTM.. A similar topical aromatic composition is described in U.S. Pat. No. 5,322,689 but without a high level of petrolatum. Instead, a carboxylic acid copolymer is used. This composition, however, has the consistency of a fluid like the VICK'S product and is also applied topically. These products have significant drawbacks. Petroleum-based fluids are greasy and tend to be spread onto areas that are not intended. In addition, the fingers of the user must be dipped into the fluid product and, consequently, the product gets onto hands, on clothing, and can even be spread to areas where it can cause irritation, such as the nasal mucosa or the eyes. When applied by a healthcare worker, the smell of the decongestant can be carried away on hands and clothing. Moreover, because of the fluidity of such these products, they soon rub off onto the user's clothing and bed linens.
Another shortcoming of prior decongestants is the limitation on the rate of evaporation of the active aromatic substances. A large portion lies beneath the surface and is therefore not exposed to the air. The vaporization of this sub-surface material is therefore inhibited. One object of the present invention is to overcome this deficiency by finding a way to promote volatilization of active decongestant agents.
In view of these and other deficiencies of the prior art, it is one object of the present invention to provide a decongestant for alleviating one or more of the symptoms of nasal congestion, cough, colds or bronchial congestion but which is also comfortable to use, non-greasy and can be easily and quickly removed from the skin when no longer needed.
Another object is to provide an oral and nasal decongestant which readily evolves decongestant vapor that can be inhaled through the mouth or nose but will not spread out on the skin or be accidentally transferred to clothing.
Still another object of the invention is to provide an improved decongestant which readily diffuses into the air but still provides therapeutic effects that are long lasting.
A further object is to provide an improved decongestant and carrier for inhalation therapy which if desired can be structured to also provide analgesic effects through the skin.
These and other more detailed and specific objects of the present invention will be better understood by reference to the following figures and detailed description which illustrate by way of example of but a few of the various forms of the invention within the scope of the appended claims.